Eller, 35, was first reported missing May 9 after she went on a hike in Makawao Forest Reserve in Maui.
The instructor was discovered in a deep ravine, according to a post on a Facebook page devoted to finding Eller.
"She got lost and was stuck and slightly injured in the forest- way way out," the post read. "... Between two waterfalls down a deep ravine in a creek bed.
The post added: "She is being air evacuated now. She just talked to her father on the phone. Amanda Eller is ALIVE!!!!"
She was found Friday afternoon by lead searchers Chris Berquist and Javier Cantellops, who heard her calling them from the ravine.
In a happy press conference, her father, John Eller, said he is thrilled Amanda was found alive.
“A lot of tears,” John said of the moment he heard she'd been found. “It looks like she lost a little weight, got a really good suntan. Sun took its toll.
"It was a rough journey. It was her mental strength and fortitude, her belief in herself that kept her at it.”
The family never gave up hope Amanda would be found alive, continuing the search for her even after officials could no longer devote the manpower to it.
“They did a terrific job while we had them, 72 hours is a typical search limit here apparently,” read a post on the Find Amanda page. “WE, however, have just begun the forest search. Volunteers please search the forest every day until we find her.”
Amanda is being treated at Maui Memorial Hospital.
Berquist, one of the people who found her, said she was in shockingly good shape.
"She was very alert, she knew her father's phone number, she knew who she was, where she was, knew exactly how long she had been out there — very surprised to see us," Berquist told ABC News. "I've never felt something quite that overpowering."